H. P. Wang, S. Poedts, A. Lani, M. Brchnelova, T. Baratashvili, L. Linan, F. Zhang, D. W. Hou, Y. H. Zhou
MHD coronal models are critical in the Sun-to-Earth model chain and the most complex and computationally intensive component, particularly the time-evolving coronal models, typically driven by a series of time-evolving photospheric magnetograms. There is an urgent need to develop efficient and reliable time-evolving MHD coronal models to further improve our ability to predict space weather. COCONUT is a rapidly developing MHD coronal model. Adopting the efficient implicit algorithm makes it suitable for performing computationally intensive time-evolving coronal simulations. This paper aims to extend COCONUT to an efficient time-evolving MHD coronal model. In this MHD model, as usual, an implicit temporal integration algorithm is adopted to avoid the CFL stability restriction and increase computational efficiency by large time steps. The Newton iteration method is applied within each time step to enhance the temporal accuracy. The unstructured geodesic mesh is used for flexibility in mesh division and to avoid degeneracy at the poles. Furthermore, an HLL Riemann solver with a self-adjustable dissipation term accommodates both low- and high-speed flows. A series of time-evolving photospheric magnetograms are utilized to drive the evolution of coronal structures from the solar surface to 25Rs during two Carrington rotations (CRs) around the 2019 eclipse in an inertial coordinate system. It shows that COCONUT can mimic the coronal evolution during a full CR within 9 hours (1080 CPU cores, 1.5M cells). We also compare the simulation results of time-evolving versus quasi-steady-state coronal simulations in the thermodynamic MHD model to validate the time-evolving approach. Additionally, we evaluate the effect of time steps on the simulation results to find an optimal time step that simultaneously maintains high efficiency and necessary numerical stability and accuracy.
{"title":"An efficient, time-evolving, global MHD coronal model based on COCONUT","authors":"H. P. Wang, S. Poedts, A. Lani, M. Brchnelova, T. Baratashvili, L. Linan, F. Zhang, D. W. Hou, Y. H. Zhou","doi":"arxiv-2409.02043","DOIUrl":"https://doi.org/arxiv-2409.02043","url":null,"abstract":"MHD coronal models are critical in the Sun-to-Earth model chain and the most\u0000complex and computationally intensive component, particularly the time-evolving\u0000coronal models, typically driven by a series of time-evolving photospheric\u0000magnetograms. There is an urgent need to develop efficient and reliable\u0000time-evolving MHD coronal models to further improve our ability to predict\u0000space weather. COCONUT is a rapidly developing MHD coronal model. Adopting the\u0000efficient implicit algorithm makes it suitable for performing computationally\u0000intensive time-evolving coronal simulations. This paper aims to extend COCONUT\u0000to an efficient time-evolving MHD coronal model. In this MHD model, as usual,\u0000an implicit temporal integration algorithm is adopted to avoid the CFL\u0000stability restriction and increase computational efficiency by large time\u0000steps. The Newton iteration method is applied within each time step to enhance\u0000the temporal accuracy. The unstructured geodesic mesh is used for flexibility\u0000in mesh division and to avoid degeneracy at the poles. Furthermore, an HLL\u0000Riemann solver with a self-adjustable dissipation term accommodates both low-\u0000and high-speed flows. A series of time-evolving photospheric magnetograms are\u0000utilized to drive the evolution of coronal structures from the solar surface to\u000025Rs during two Carrington rotations (CRs) around the 2019 eclipse in an\u0000inertial coordinate system. It shows that COCONUT can mimic the coronal\u0000evolution during a full CR within 9 hours (1080 CPU cores, 1.5M cells). We also\u0000compare the simulation results of time-evolving versus quasi-steady-state\u0000coronal simulations in the thermodynamic MHD model to validate the\u0000time-evolving approach. Additionally, we evaluate the effect of time steps on\u0000the simulation results to find an optimal time step that simultaneously\u0000maintains high efficiency and necessary numerical stability and accuracy.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223600","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Miguel Ralha, Pedro Teles, Nuno Santos, Daniel Matthiä, Thomas Berger, Marta Cortesão
Exposure to cosmic radiation is a major concern in space exploration. On the Martian surface, a complex radiation field is present, formed by a constant influx of galactic cosmic radiation and the secondary particles produced by their interaction with the planet's atmosphere and regolith. In this work, a Martian environment model was developed using MCNP6 following the guidelines of the 1st Mars Space Radiation Modeling Workshop. The accuracy of the model was tested by comparing particle spectra and dose rate results with other model results and measurements from the Radiation Assessment Detector (RAD) onboard the Curiosity rover, taken between November 15, 2015, and January 15, 2016. The ICRP's voxel-type computational phantoms were then implemented into the code. Organ dose and effective dose equivalent were assessed for the same time period. The viability of a mission on the surface of Mars for extended periods of time under the assumed conditions was here investigated.
{"title":"Effective dose equivalent estimation for humans on Mars","authors":"Miguel Ralha, Pedro Teles, Nuno Santos, Daniel Matthiä, Thomas Berger, Marta Cortesão","doi":"arxiv-2409.02001","DOIUrl":"https://doi.org/arxiv-2409.02001","url":null,"abstract":"Exposure to cosmic radiation is a major concern in space exploration. On the\u0000Martian surface, a complex radiation field is present, formed by a constant\u0000influx of galactic cosmic radiation and the secondary particles produced by\u0000their interaction with the planet's atmosphere and regolith. In this work, a\u0000Martian environment model was developed using MCNP6 following the guidelines of\u0000the 1st Mars Space Radiation Modeling Workshop. The accuracy of the model was\u0000tested by comparing particle spectra and dose rate results with other model\u0000results and measurements from the Radiation Assessment Detector (RAD) onboard\u0000the Curiosity rover, taken between November 15, 2015, and January 15, 2016. The\u0000ICRP's voxel-type computational phantoms were then implemented into the code.\u0000Organ dose and effective dose equivalent were assessed for the same time\u0000period. The viability of a mission on the surface of Mars for extended periods\u0000of time under the assumed conditions was here investigated.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178408","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
H. P. Wang, J. H. Guo, L. P. Yang, S. Poedts, F. Zhang, A. Lani, T. Baratashvili, L. Linan, R. Lin, Y. Guo
CMEs are one of the main drivers of space weather. However, robust and efficient numerical modeling of the initial stages of CME propagation and evolution process in the sub-Alfvenic corona is still lacking. Based on the highly efficient quasi-steady-state implicit MHD coronal model (Feng et al. 2021; Wang et al. 2022a), we further develop an efficient and time-accurate coronal model and employ it to simulate the CME's evolution and propagation. A pseudo-time marching method, where a pseudo time, tau, is introduced at each physical time step to update the solution by solving a steady-state problem on tau, is devised to improve the temporal accuracy. Moreover, an RBSL flux rope whose axis can be designed in an arbitrary shape is inserted into the background corona to trigger the CME event. We call it the SIP-IFVM coronal model and utilize it to simulate a CME evolution process from the solar surface to 20 Rs in the background corona of CR 2219. It can finish the CME simulation covering 6 hours of physical time by less than 0.5 hours (192 CPU cores, 1 M cells) without much loss in temporal accuracy. Besides, an ad hoc simulation with initial magnetic fields artificially increased shows that this model can effectively deal with time-dependent low-beta problems (beta<0.0005). Additionally, an Orszag-Tang MHD vortex flow simulation demonstrates that the pseudo-time-marching method adopted in this coronal model is also capable of simulating small-scale unsteady-state flows. The simulation results show that this MHD coronal model is very efficient and numerically stable and is promising to timely and accurately simulate time-varying events in solar corona with low plasma beta.
{"title":"SIP-IFVM: An efficient time-accurate implicit MHD model of corona and CME with strong magnetic field","authors":"H. P. Wang, J. H. Guo, L. P. Yang, S. Poedts, F. Zhang, A. Lani, T. Baratashvili, L. Linan, R. Lin, Y. Guo","doi":"arxiv-2409.02022","DOIUrl":"https://doi.org/arxiv-2409.02022","url":null,"abstract":"CMEs are one of the main drivers of space weather. However, robust and\u0000efficient numerical modeling of the initial stages of CME propagation and\u0000evolution process in the sub-Alfvenic corona is still lacking. Based on the\u0000highly efficient quasi-steady-state implicit MHD coronal model (Feng et al.\u00002021; Wang et al. 2022a), we further develop an efficient and time-accurate\u0000coronal model and employ it to simulate the CME's evolution and propagation. A\u0000pseudo-time marching method, where a pseudo time, tau, is introduced at each\u0000physical time step to update the solution by solving a steady-state problem on\u0000tau, is devised to improve the temporal accuracy. Moreover, an RBSL flux rope\u0000whose axis can be designed in an arbitrary shape is inserted into the\u0000background corona to trigger the CME event. We call it the SIP-IFVM coronal\u0000model and utilize it to simulate a CME evolution process from the solar surface\u0000to 20 Rs in the background corona of CR 2219. It can finish the CME simulation\u0000covering 6 hours of physical time by less than 0.5 hours (192 CPU cores, 1 M\u0000cells) without much loss in temporal accuracy. Besides, an ad hoc simulation\u0000with initial magnetic fields artificially increased shows that this model can\u0000effectively deal with time-dependent low-beta problems (beta<0.0005).\u0000Additionally, an Orszag-Tang MHD vortex flow simulation demonstrates that the\u0000pseudo-time-marching method adopted in this coronal model is also capable of\u0000simulating small-scale unsteady-state flows. The simulation results show that\u0000this MHD coronal model is very efficient and numerically stable and is\u0000promising to timely and accurately simulate time-varying events in solar corona\u0000with low plasma beta.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142223601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Daniele Belardinelli, Simone Benella, Mirko Stumpo, Giuseppe Consolini
Kinetic scale dynamics in weakly-collisional space plasmas usually exhibits a self-similar statistics of magnetic field fluctuations which implies the existence of an invariant probability density function (master curve). We provide an analytical derivation of the master curve by assuming that perpendicular fluctuations can be modeled through a scale-dependent Langevin equation. In our model, magnetic field fluctuations are the stochastic variable and their scale-to-scale evolution is assumed to be a Langevin process. We propose a formal derivation of the master curve describing the statistics of the fluctuations at kinetic scales. Model predictions are tested on independent data samples of fast solar wind measured near the Sun by Parker Solar Probe and near the Earth by Cluster. The master curve is a generalization of the Kappa distribution with two parameters: one regulating the tails and the other one controlling the asymmetry. Model predictions match the spacecraft observations up to 5$sigma$ and even beyond in the case of perpendicular magnetic field fluctuations.
{"title":"Derivation of generalized Kappa distribution from scaling properties of solar wind magnetic field fluctuations at kinetic scales","authors":"Daniele Belardinelli, Simone Benella, Mirko Stumpo, Giuseppe Consolini","doi":"arxiv-2409.01775","DOIUrl":"https://doi.org/arxiv-2409.01775","url":null,"abstract":"Kinetic scale dynamics in weakly-collisional space plasmas usually exhibits a\u0000self-similar statistics of magnetic field fluctuations which implies the\u0000existence of an invariant probability density function (master curve). We\u0000provide an analytical derivation of the master curve by assuming that\u0000perpendicular fluctuations can be modeled through a scale-dependent Langevin\u0000equation. In our model, magnetic field fluctuations are the stochastic variable\u0000and their scale-to-scale evolution is assumed to be a Langevin process. We\u0000propose a formal derivation of the master curve describing the statistics of\u0000the fluctuations at kinetic scales. Model predictions are tested on independent\u0000data samples of fast solar wind measured near the Sun by Parker Solar Probe and\u0000near the Earth by Cluster. The master curve is a generalization of the Kappa\u0000distribution with two parameters: one regulating the tails and the other one\u0000controlling the asymmetry. Model predictions match the spacecraft observations\u0000up to 5$sigma$ and even beyond in the case of perpendicular magnetic field\u0000fluctuations.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jiaming Wang, William H. Matthaeus, Rohit Chhiber, Sohom Roy, Rayta A. Pradata, Francesco Pecora, Yan Yang
We present a broad review of 1/f noise observations in the heliosphere, and discuss and complement the theoretical background of generic 1/f models as relevant to NASA's Polarimeter to Unify the Corona and Heliosphere (PUNCH) mission. First observed in the voltage fluctuations of vacuum tubes, the scale-invariant 1/f spectrum has since been identified across a wide array of natural and artificial systems, including heart rate fluctuations and loudness patterns in musical compositions. In the solar wind, the interplanetary magnetic field trace spectrum exhibits 1/f scaling within the frequency range from around 2e-6 Hz to 1e-4 Hz at 1 au. One compelling mechanism for the generation of 1/f noise is the superposition principle, where a composite 1/f spectrum arises from the superposition of a collection of individual power-law spectra characterized by a scale-invariant distribution of correlation times. In the context of the solar wind, such a superposition could originate from scale-invariant reconnection processes in the corona. Further observations have detected 1/f signatures in the photosphere and corona at frequency ranges compatible with those observed at 1 au, suggesting an even lower altitude origin of 1/f spectrum in the solar dynamo itself. This hypothesis is bolstered by dynamo experiments and simulations that indicate inverse cascade activities, which can be linked to successive flux tube reconnections beneath the corona, and are known to generate 1/f noise possibly through nonlocal interactions at the largest scales. Conversely, models positing in situ generation of 1/f signals face causality issues in explaining the low-frequency portion of the 1/f spectrum. Understanding 1/f noise in the solar wind may inform central problems in heliospheric physics, such as the solar dynamo, coronal heating, the origin of the solar wind, and the nature of interplanetary turbulence.
{"title":"$1/f$ Noise in the Heliosphere: A Target for PUNCH Science","authors":"Jiaming Wang, William H. Matthaeus, Rohit Chhiber, Sohom Roy, Rayta A. Pradata, Francesco Pecora, Yan Yang","doi":"arxiv-2409.02255","DOIUrl":"https://doi.org/arxiv-2409.02255","url":null,"abstract":"We present a broad review of 1/f noise observations in the heliosphere, and\u0000discuss and complement the theoretical background of generic 1/f models as\u0000relevant to NASA's Polarimeter to Unify the Corona and Heliosphere (PUNCH)\u0000mission. First observed in the voltage fluctuations of vacuum tubes, the\u0000scale-invariant 1/f spectrum has since been identified across a wide array of\u0000natural and artificial systems, including heart rate fluctuations and loudness\u0000patterns in musical compositions. In the solar wind, the interplanetary\u0000magnetic field trace spectrum exhibits 1/f scaling within the frequency range\u0000from around 2e-6 Hz to 1e-4 Hz at 1 au. One compelling mechanism for the\u0000generation of 1/f noise is the superposition principle, where a composite 1/f\u0000spectrum arises from the superposition of a collection of individual power-law\u0000spectra characterized by a scale-invariant distribution of correlation times.\u0000In the context of the solar wind, such a superposition could originate from\u0000scale-invariant reconnection processes in the corona. Further observations have\u0000detected 1/f signatures in the photosphere and corona at frequency ranges\u0000compatible with those observed at 1 au, suggesting an even lower altitude\u0000origin of 1/f spectrum in the solar dynamo itself. This hypothesis is bolstered\u0000by dynamo experiments and simulations that indicate inverse cascade activities,\u0000which can be linked to successive flux tube reconnections beneath the corona,\u0000and are known to generate 1/f noise possibly through nonlocal interactions at\u0000the largest scales. Conversely, models positing in situ generation of 1/f\u0000signals face causality issues in explaining the low-frequency portion of the\u00001/f spectrum. Understanding 1/f noise in the solar wind may inform central\u0000problems in heliospheric physics, such as the solar dynamo, coronal heating,\u0000the origin of the solar wind, and the nature of interplanetary turbulence.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178405","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shaaban M. Shaaban, M. Lazar, R. A. López, P. H. Yoon, S. Poedts
In situ observations by the Parker Solar Probe (PSP) have revealed new properties of the proton velocity distributions, including hammerhead features that suggest non-isotropic broadening of the beams. The present work proposes a very plausible explanation for the formation of these populations through the action of a proton firehose-like instability triggered by the proton beam. The quasi-linear (QL) theory proposed here shows that the resulting right-hand (RH) waves have two consequences on the protons: (i) reduce the relative drift between the beam and the core, but above all, (ii) induce a strong perpendicular temperature anisotropy, specific to the observed hammerhead ion strahl. Moreover, the long-run QL results suggest that these hammerhead distributions are rather transitory states, still subject to relaxation mechanisms, of which instabilities like the one discussed here are very likely involved.
{"title":"Decoding the formation of hammerhead ion populations observed by Parker Solar Probe","authors":"Shaaban M. Shaaban, M. Lazar, R. A. López, P. H. Yoon, S. Poedts","doi":"arxiv-2409.01997","DOIUrl":"https://doi.org/arxiv-2409.01997","url":null,"abstract":"In situ observations by the Parker Solar Probe (PSP) have revealed new\u0000properties of the proton velocity distributions, including hammerhead features\u0000that suggest non-isotropic broadening of the beams. The present work proposes a\u0000very plausible explanation for the formation of these populations through the\u0000action of a proton firehose-like instability triggered by the proton beam. The\u0000quasi-linear (QL) theory proposed here shows that the resulting right-hand (RH)\u0000waves have two consequences on the protons: (i) reduce the relative drift\u0000between the beam and the core, but above all, (ii) induce a strong\u0000perpendicular temperature anisotropy, specific to the observed hammerhead ion\u0000strahl. Moreover, the long-run QL results suggest that these hammerhead\u0000distributions are rather transitory states, still subject to relaxation\u0000mechanisms, of which instabilities like the one discussed here are very likely\u0000involved.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178425","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Carmelo Magnafico, Umberto De Filippis, Francesco Santoli, Carlo Lefevre, Marco Lucente, David Lucchesi, Emiliano Fiorenza, Roberto Peron, Valerio Iafolla
The Italian Spring Accelerometer (ISA) is a three axis mass-spring accelerometer, one of the payloads of the BepiColombo joint space mission between the European Space Agency (ESA) and the Japan Aerospace Exploration Agency (JAXA). At launch in October 2018, BepiColombo started its seven-year cruise as a stack of three different modules, overall named Mercury Composite Spacecraft (MCS). The spacecraft will provide BepiColombo the necessary Delta V to reach Mercury with its electric thrusters and along with one, two and six gravity assists, respectively with Earth, Venus and Mercury. The accelerometer is accommodated on the Mercury Planetary Orbiter (MPO) module and, jointly with the Ka-band Transponder (KaT) tracking data, will primarily serve the BepiColombo Radio Science Experiment (BC-RSE). During the second Venus swing-by, strong tidal effect and external perturbations was expected to act on the spacecraft and to become detectable by ISA. The swing-by had a closest approach of about 550 km and the gravity gradient expected on the IDA sensing elements was perfectly measured. Hence, in this paper, the first direct Gravity Gradient effect detection generated by an extraterrestrial body is shown. Nevertheless, around the closest approach, the measurements evidenced a spurious acceleration event lasting for several minutes. This work, exploiting information on the Attitude and Orbit Control System (AOCS) commanded torques, focuses and analyses this ISA acceleration signal, ascribing it to a net force really acting on the MCS spacecraft. Furthermore, using an estimation method, the application point of the force is confined to an area close to the MPO radiator.
意大利弹簧加速度计（ISA）是一个三轴质量弹簧加速度计，是欧洲空间局（ESA）和日本宇宙航空研究开发机构（JAXA）之间的BepiColombo联合太空任务的有效载荷之一。2018年10月发射时，BepiColombo作为三个不同模块的堆叠开始了其为期七年的巡航，总体命名为水星复合航天器（MCS）。该航天器将为 BepiColombo 提供必要的德尔塔 V，以便利用其电动推进器到达水星，同时还将分别为地球、金星和水星提供一次、两次和六次重力辅助。加速度计安装在水星行星轨道器（MPO）模块上，与 Ka 波段转发器（KaT）跟踪数据一起，将主要为贝皮科伦坡无线电科学实验（BC-RSE）服务。在第二次掠过金星期间，预计会有强烈的潮汐效应和外部扰动作用在航天器上，并会被国际空间站探测到。这次绕行的最近距离约为 550 公里，国际空间站传感元件上预期的重力梯度得到了完美的测量。因此，本文首次直接探测到了由地外天体产生的重力梯度效应。然而，在最近接近时，测量结果表明出现了持续数分钟的假加速事件。这项工作利用姿态和轨道控制系统（AOCS）指令扭矩的信息，聚焦并分析了这一ISA加速信号，将其归因于真正作用于MCS航天器的净力。此外，利用一种估算方法，该力的作用点被限制在靠近 MPOradiator 的区域。
{"title":"Italian Spring Accelerometer measurements of unexpected Non Gravitational Perturbation during BepiColombo second Venus swing-by","authors":"Carmelo Magnafico, Umberto De Filippis, Francesco Santoli, Carlo Lefevre, Marco Lucente, David Lucchesi, Emiliano Fiorenza, Roberto Peron, Valerio Iafolla","doi":"arxiv-2409.02015","DOIUrl":"https://doi.org/arxiv-2409.02015","url":null,"abstract":"The Italian Spring Accelerometer (ISA) is a three axis mass-spring\u0000accelerometer, one of the payloads of the BepiColombo joint space mission\u0000between the European Space Agency (ESA) and the Japan Aerospace Exploration\u0000Agency (JAXA). At launch in October 2018, BepiColombo started its seven-year\u0000cruise as a stack of three different modules, overall named Mercury Composite\u0000Spacecraft (MCS). The spacecraft will provide BepiColombo the necessary Delta V\u0000to reach Mercury with its electric thrusters and along with one, two and six\u0000gravity assists, respectively with Earth, Venus and Mercury. The accelerometer\u0000is accommodated on the Mercury Planetary Orbiter (MPO) module and, jointly with\u0000the Ka-band Transponder (KaT) tracking data, will primarily serve the\u0000BepiColombo Radio Science Experiment (BC-RSE). During the second Venus\u0000swing-by, strong tidal effect and external perturbations was expected to act on\u0000the spacecraft and to become detectable by ISA. The swing-by had a closest\u0000approach of about 550 km and the gravity gradient expected on the IDA sensing\u0000elements was perfectly measured. Hence, in this paper, the first direct Gravity\u0000Gradient effect detection generated by an extraterrestrial body is shown.\u0000Nevertheless, around the closest approach, the measurements evidenced a\u0000spurious acceleration event lasting for several minutes. This work, exploiting\u0000information on the Attitude and Orbit Control System (AOCS) commanded torques,\u0000focuses and analyses this ISA acceleration signal, ascribing it to a net force\u0000really acting on the MCS spacecraft. Furthermore, using an estimation method,\u0000the application point of the force is confined to an area close to the MPO\u0000radiator.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178412","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
O. Anton, I. Bröckel, D. Derr, A. Fieguth, M. Franzke, M. Gärtner, E. Giese, J. S. Haase, J. Hamann, A. Heidt, S. Kanthak, C. Klempt, J. Kruse, M. Krutzik, S. Kubitza, C. Lotz, K. Müller, J. Pahl, E. M. Rasel, M. Schiemangk, W. P. Schleich, S. Schwertfeger, A. Wicht, L. Wörner
The INTENTAS project aims to develop an atomic sensor utilizing entangled Bose-Einstein condensates (BECs) in a microgravity environment. This key achievement is necessary to advance the capability for measurements that benefit from both entanglement-enhanced sensitivities and extended interrogation times. The project addresses significant challenges related to size, weight, and power management (SWaP) specific to the experimental platform at the Einstein-Elevator in Hannover. The design ensures a low-noise environment essential for the creation and detection of entanglement. Additionally, the apparatus features an innovative approach to the all-optical creation of BECs, providing a flexible system for various configurations and meeting the requirements for rapid turnaround times. Successful demonstration of this technology in the Einstein-Elevator will pave the way for a future deployment in space, where its potential applications will unlock high-precision quantum sensing.
{"title":"INTENTAS -- An entanglement-enhanced atomic sensor for microgravity","authors":"O. Anton, I. Bröckel, D. Derr, A. Fieguth, M. Franzke, M. Gärtner, E. Giese, J. S. Haase, J. Hamann, A. Heidt, S. Kanthak, C. Klempt, J. Kruse, M. Krutzik, S. Kubitza, C. Lotz, K. Müller, J. Pahl, E. M. Rasel, M. Schiemangk, W. P. Schleich, S. Schwertfeger, A. Wicht, L. Wörner","doi":"arxiv-2409.01051","DOIUrl":"https://doi.org/arxiv-2409.01051","url":null,"abstract":"The INTENTAS project aims to develop an atomic sensor utilizing entangled\u0000Bose-Einstein condensates (BECs) in a microgravity environment. This key\u0000achievement is necessary to advance the capability for measurements that\u0000benefit from both entanglement-enhanced sensitivities and extended\u0000interrogation times. The project addresses significant challenges related to\u0000size, weight, and power management (SWaP) specific to the experimental platform\u0000at the Einstein-Elevator in Hannover. The design ensures a low-noise\u0000environment essential for the creation and detection of entanglement.\u0000Additionally, the apparatus features an innovative approach to the all-optical\u0000creation of BECs, providing a flexible system for various configurations and\u0000meeting the requirements for rapid turnaround times. Successful demonstration\u0000of this technology in the Einstein-Elevator will pave the way for a future\u0000deployment in space, where its potential applications will unlock\u0000high-precision quantum sensing.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178424","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jeet Majumdar, Shubhadeep Nag, Tejender S Thakur, Subramanian Yashonath, Bhalamurugan Sivaraman, Prabal K. Maiti
Ethanethiol (C$_2$H$_5$SH), a molecule detected in the interstellar medium (ISM), indicates the rich chemistry involving sulfur atoms. However, its behavior at low temperatures remains elusive, particularly the reported transition from an amorphous phase to a crystal. This study employs classical molecular dynamics (MD) simulations to reproduce the liquid-state properties of ethanethiol and to simulate the initial amorphous state of ethanethiol films deposited on a KBr substrate. The amorphous ethanethiol did not show spontaneous crystallization upon increasing temperature. Also, ethanethiol ice crystals exhibit melting behavior on KBr substrate at elevated temperatures. Our MD simulations of thin ice samples do not show any signature reversible phase change. It will be interesting to continue this study with a thicker sample, which is beyond our current computational means. These findings underscore the complexity of icy mantle morphology on cold ISM dust grains.
{"title":"Deciphering Interstellar Ice Morphology: Atomistic Simulations Reveal the Complex Behavior of Ethanethiol","authors":"Jeet Majumdar, Shubhadeep Nag, Tejender S Thakur, Subramanian Yashonath, Bhalamurugan Sivaraman, Prabal K. Maiti","doi":"arxiv-2409.00975","DOIUrl":"https://doi.org/arxiv-2409.00975","url":null,"abstract":"Ethanethiol (C$_2$H$_5$SH), a molecule detected in the interstellar medium\u0000(ISM), indicates the rich chemistry involving sulfur atoms. However, its\u0000behavior at low temperatures remains elusive, particularly the reported\u0000transition from an amorphous phase to a crystal. This study employs classical\u0000molecular dynamics (MD) simulations to reproduce the liquid-state properties of\u0000ethanethiol and to simulate the initial amorphous state of ethanethiol films\u0000deposited on a KBr substrate. The amorphous ethanethiol did not show\u0000spontaneous crystallization upon increasing temperature. Also, ethanethiol ice\u0000crystals exhibit melting behavior on KBr substrate at elevated temperatures.\u0000Our MD simulations of thin ice samples do not show any signature reversible\u0000phase change. It will be interesting to continue this study with a thicker\u0000sample, which is beyond our current computational means. These findings\u0000underscore the complexity of icy mantle morphology on cold ISM dust grains.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Bruce T. Tsurutani, Abhijit Sen, Rajkumar Hajra, Gurbax S. Lakhina, Richard B. Horne, Tohru Hada
Updated summaries of the August 1972 and March 1989 space weather events have been constructed. The features of these two events are compared to the Carrington 1859 event and a few other major space weather events. It is concluded that solar active regions release energy in a variety of forms (X-rays, EUV photons, visible light, coronal mass ejection (CME) plasmas and fields) and they in turn can produce other energetic effects (solar energetic particles (SEPs), magnetic storms) in a variety of ways. It is clear that there is no strong one-to-one relationship between these various energy sinks. The energy is often distributed differently from one space weather event to the next. Concerning SEPs accelerated at interplanetary CME (ICME) shocks, it is concluded that the Fermi mechanism associated with quasi-parallel shocks is relatively weak and that the gradient drift mechanism (electric fields) at quasi-perpendicular shocks will produce harder spectra and higher fluxes. If the 4 Augusut 1972 intrinsic magnetic cloud condition (southward interplanetary magnetic field instead of northward) and the interplanetary Sun to 1 au conditions were different, a 4 August 1972 magnetic storm and magnetospheric dawn-to-dusk electric fields substantially larger than the Carrington event would have occurred. Under these special interplanetary conditions, a Miyake et al. (2012)-like extreme SEP event may have been formed. The long duration complex 1989 storm was probably greater than the Carrington storm in the sense that the total ring current particle energy was larger.
{"title":"Review of the August 1972 and March 1989 Space Weather Events: Can We Learn Anything New From Them?","authors":"Bruce T. Tsurutani, Abhijit Sen, Rajkumar Hajra, Gurbax S. Lakhina, Richard B. Horne, Tohru Hada","doi":"arxiv-2409.00452","DOIUrl":"https://doi.org/arxiv-2409.00452","url":null,"abstract":"Updated summaries of the August 1972 and March 1989 space weather events have\u0000been constructed. The features of these two events are compared to the\u0000Carrington 1859 event and a few other major space weather events. It is\u0000concluded that solar active regions release energy in a variety of forms\u0000(X-rays, EUV photons, visible light, coronal mass ejection (CME) plasmas and\u0000fields) and they in turn can produce other energetic effects (solar energetic\u0000particles (SEPs), magnetic storms) in a variety of ways. It is clear that there\u0000is no strong one-to-one relationship between these various energy sinks. The\u0000energy is often distributed differently from one space weather event to the\u0000next. Concerning SEPs accelerated at interplanetary CME (ICME) shocks, it is\u0000concluded that the Fermi mechanism associated with quasi-parallel shocks is\u0000relatively weak and that the gradient drift mechanism (electric fields) at\u0000quasi-perpendicular shocks will produce harder spectra and higher fluxes. If\u0000the 4 Augusut 1972 intrinsic magnetic cloud condition (southward interplanetary\u0000magnetic field instead of northward) and the interplanetary Sun to 1 au\u0000conditions were different, a 4 August 1972 magnetic storm and magnetospheric\u0000dawn-to-dusk electric fields substantially larger than the Carrington event\u0000would have occurred. Under these special interplanetary conditions, a Miyake et\u0000al. (2012)-like extreme SEP event may have been formed. The long duration\u0000complex 1989 storm was probably greater than the Carrington storm in the sense\u0000that the total ring current particle energy was larger.","PeriodicalId":501423,"journal":{"name":"arXiv - PHYS - Space Physics","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2024-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142178410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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